The present invention relates to an improved seed planter attachment of the type described in my U.S. Pat. No. 4,520,742 which issued on June 4, 1985, entitled "Seed Planter Attachment for Chisel Plow" which is incorporated herein by reference.
No-till farming methods conventionally employ chisel plows which are elongate pointed chisels mounted to the undercarriage of a frame which has wheels and is adapted to be drawn behind a tractor or the like. In my copending application, referred to above, there was described a seed planter attachment for a chisel plow in which the seed planter is resiliently mounted to the chisel plow by means of a leaf spring rod attached to the shank of the chisel plow at any vertical location along the length thereof. The other end of the leaf spring rod supported a seed planter boot which included a fixed mounting bracket for the attachment of gauge depth wheels for regulating the vertical height of the boot. In that design the gauge depth wheels were connected to the bracket on the seed planter boot by means of a slot-engaging U-bolt which gripped the axle of the gauge depth wheels. An elongate pin was inserted through the loops of the U-bolt on the inside of the bracket to hold the axle in place. This arrangement, however, is awkward and time-consuming if modifications must be made in the field to the height of the seed planter attachment. Moreover, the design did not accommodate a single press wheel adapted to be towed in the wake of the boot to press the seeds firmly into the ground.
The bracket for the attachments of the leaf spring rod and the gauge depth wheels was fixedly mounted to the seed guide boot through which seeds were dropped from a seed-dispensing mechanism on the frame. The seed boot also included a foot for creating a narrow furrow for the seeds that followed in the wake of the chisel plow. The depth of the boot, however, could not be regulated independently of the gauge wheels. This is because any changes in the vertical height of the boot relative to the gauge wheels would necessitate a corresponding change in the position of the leaf spring rod either along the shank of the plow or along the bracket fixedly mounted to the seed planter boot. One could not provide for a change in the seed planting depth while attempting to maintain the same ground-engaging bias for the gauge wheels provided by the leaf spring rod. Moreover, the design of the foot did not provide the maximum advantage to be obtained for such a ground-engaging tool preceding the seed boot. Since the distance between the seed boot and the plow shank may be adjusted by sliding the seed tube and its associated bracket backwards and forwards along the horizontal portion of the curved spring rod, more efficient designs of the foot could be used to work the soil prior to seed planting.